feature: Add port shape

Replaces the hard-coded 2pt padding used when placing port name labels.
Configurable per element via port-name-padding on elmt (forwarded by
block and group), defaulting to 2pt to preserve existing layout.

doc/examples.typ

@@ -188,6 +188,80 @@ wire.wire("w2", ("b2-port-out", "b3-port-in2"),
           style: "zigzag")
 ```)
 
+#let group-ports = example(```
+// outside-port-names: true (default) — labels outside the border
+element.group(
+  id: "g1", name: "outside (default)",
+  stroke: (dash: "dashed"),
+  fill: util.colors.blue.lighten(60%),
+  padding: 2em,
+  outside-port-names: true,
+  port-name-padding: 4pt,
+  ports: (
+    west:  ((id: "in",  name: "D"),),
+    east:  ((id: "out", name: "Q"),),
+  ),
+  { element.block(id: "b1", w: 2, h: 1.5, x: 0, y: 0,
+      fill: util.colors.green,
+      ports: (west: ((id: "d", name: "d"),),
+              east: ((id: "q", name: "q"),))) }
+)
+wire.wire("wG1in",  ("g1-port-in", "b1-port-d"), directed: true)
+wire.wire("wG1out", ("b1-port-q",  "g1-port-out"), directed: true)
+
+// outside-port-names: false — labels inside the border (block style)
+// with extra padding via port-name-padding
+element.group(
+  id: "g2", name: "inside",
+  stroke: (dash: "dashed"),
+  fill: util.colors.orange.lighten(60%),
+  padding: 2em,
+  outside-port-names: false,
+  port-name-padding: 0.4em,
+  ports: (
+    west:  ((id: "in",  name: "D"),),
+    east:  ((id: "out", name: "Q"),),
+  ),
+  { element.block(id: "b2", w: 2, h: 1.5, x: 6, y: 0,
+      fill: util.colors.green,
+      ports: (west: ((id: "d"),), east: ((id: "q"),))) }
+)
+wire.stub("g2-port-in",  "west")
+wire.stub("g2-port-out", "east")
+```, vertical: true)
+
+#let port-shape = example(```
+// Block with pentagon-shaped ports.
+// - port-shape / port-kind / port-size are element-level defaults.
+// - Any port field (shape, kind, size, stroke, fill) overrides per port.
+// - kind: "in"  → tip points into the block (default)
+//   kind: "out" → tip points away from the block
+// - clock ports with shape: "pentagon" drop their triangle and default
+//   to a gray fill.
+element.block(
+  id: "b", w: 3, h: 3, x: 0, y: 0,
+  fill: util.colors.yellow.lighten(60%),
+  port-shape: "pentagon",
+  port-size: 1em,
+  ports: (
+    // west: default input
+    west:  ((id: "in",  name: "D"),),
+    // east: output — tip points away
+    east:  ((id: "out", name: "Q", kind: "out"),),
+    // north: clock port — pentagon replaces the triangle, gray fill
+    north: ((id: "clk", name: "CLK", clock: true),),
+    // south: styled output with per-port fill and stroke
+    south: ((id: "rdy", name: "RDY", kind: "out",
+             fill: util.colors.blue, stroke: red + 1.5pt),),
+  ),
+)
+// Wires connect at the outer end of each pentagon.
+wire.stub("b-port-in",  "west")
+wire.stub("b-port-out", "east")
+wire.stub("b-port-clk", "north")
+wire.stub("b-port-rdy", "south")
+```)
+
 #let intersection = example(```
 wire.wire("w1", ((0, 0), (1, 1)), style: "zigzag")
 wire.wire("w2", ((0, 0), (1, -.5)),

gallery/test_group_ports.typ

@@ -0,0 +1,86 @@
+// Demonstrates ports on a group element.
+// outside-port-names: true  (default) — labels outside the group border
+// outside-port-names: false           — labels inside  (block-style)
+#import "/src/lib.typ": circuit, element, util, wire
+
+#set page(width: auto, height: auto, margin: .5cm)
+
+#circuit({
+  // --- Group with port labels INSIDE (outside-port-names: false) ---
+  element.group(
+    id: "cpu",
+    name: "CPU (labels outside)",
+    name-anchor: "north",
+    stroke: (dash: "dashed"),
+    fill: util.colors.yellow.lighten(60%),
+    padding: 1em,
+    port-name-padding: .5em,
+    outside-port-names: true,
+    ports: (
+      west: (
+        (id: "in1", name: "D1"),
+        (id: "in2", name: "D2"),
+      ),
+      east: ((id: "out", name: "Q"),),
+      south: (
+        (id: "rst", name: "RST", vertical: true),
+        (id: "done", name: "DONE", vertical: true),
+      ),
+    ),
+    {
+      element.block(
+        id: "reg2",
+        w: 2.5,
+        h: 3,
+        x: 0,
+        y: 0,
+        fill: util.colors.green,
+        ports: (
+          west: ((id: "d1"), (id: "d2")),
+          east: ((id: "q"),),
+          north: ((id: "clk", clock: true),),
+        ),
+      )
+    },
+  )
+  // --- Group with port labels INSIDE (outside-port-names: false) ---
+  element.group(
+    id: "cpu2",
+    name: "CPU (labels inside)",
+    name-anchor: "north",
+    stroke: (dash: "dashed"),
+    fill: util.colors.yellow.lighten(60%),
+    padding: 4em,
+    outside-port-names: false,
+    port-name-padding: 0.5em,
+    ports: (
+      west: (
+        (id: "in1", name: "D1"),
+        (id: "in2", name: "D2"),
+      ),
+      east: ((id: "out", name: "Q"),),
+      south: (
+        (id: "rst", name: "RST", vertical: true),
+        (id: "done", name: "DONE", vertical: true),
+      ),
+    ),
+    {
+      element.block(
+        id: "reg2",
+        w: 2.5,
+        h: 3,
+        x: 10,
+        y: 0,
+        fill: util.colors.green,
+        ports: (
+          west: ((id: "d1"), (id: "d2")),
+          east: ((id: "q"),),
+          north: ((id: "clk", clock: true),),
+        ),
+      )
+    },
+  )
+  wire.stub("cpu2-port-in1", "west", name: "A")
+  wire.stub("cpu2-port-in2", "west", name: "B")
+  wire.stub("cpu2-port-out", "east", name: "Q")
+})

gallery/test_port_shape.typ

@@ -0,0 +1,117 @@
+// Demonstrates pentagon-shaped ports.
+//
+// - Element-level defaults: `port-shape`, `port-kind`, `port-size`.
+// - Per-port overrides: `shape`, `kind`, `size`, `stroke`, `fill`.
+// - Wire endpoints connect at the outer end of each pentagon.
+// - Clock ports with pentagon shape drop the clock triangle and default
+//   to a gray fill.
+#import "/src/lib.typ": circuit, element, util, wire
+
+#set page(width: auto, height: auto, margin: .5cm)
+
+#circuit({
+  // -----------------------------------------------------------------
+  // 1) All four sides × input/output
+  // -----------------------------------------------------------------
+  element.block(
+    id: "grid", w: 4, h: 4, x: 0, y: 0,
+    name: "sides × in/out", name-anchor: "center",
+    fill: util.colors.yellow.lighten(60%),
+    port-shape: "pentagon",
+    ports: (
+      west:  (
+        (id: "wi", name: "W-in"),
+        (id: "wo", name: "W-out", kind: "out"),
+      ),
+      east:  (
+        (id: "ei", name: "E-in"),
+        (id: "eo", name: "E-out", kind: "out"),
+      ),
+      north: (
+        (id: "ni", name: "N-in",  vertical: true),
+        (id: "no", name: "N-out", kind: "out", vertical: true),
+      ),
+      south: (
+        (id: "si", name: "S-in",  vertical: true),
+        (id: "so", name: "S-out", kind: "out", vertical: true),
+      ),
+    ),
+  )
+
+  // -----------------------------------------------------------------
+  // 2) Per-port styling: fill and stroke overrides + size override
+  // -----------------------------------------------------------------
+  element.block(
+    id: "styled", w: 3, h: 3, x: 10, y: 0,
+    name: "per-port styling", name-anchor: "center",
+    fill: util.colors.green.lighten(40%),
+    port-shape: "pentagon",
+    ports: (
+      west:  ((id: "a", name: "A", fill: util.colors.blue),),
+      east:  ((id: "b", name: "B", kind: "out",
+               stroke: red + 1.5pt, fill: util.colors.pink),),
+      north: ((id: "c", name: "C", size: 1.5em),),
+      south: ((id: "d", name: "D", kind: "out",
+               fill: util.colors.orange),),
+    ),
+  )
+
+  // -----------------------------------------------------------------
+  // 3) Clock port with pentagon → gray fill, no triangle
+  // -----------------------------------------------------------------
+  element.block(
+    id: "clk", w: 3, h: 2.5, x: 16, y: 0,
+    name: "clock + pentagon", name-anchor: "center",
+    fill: util.colors.orange.lighten(60%),
+    port-shape: "pentagon",
+    ports: (
+      west:  ((id: "d", name: "D"),),
+      east:  ((id: "q", name: "Q", kind: "out"),),
+      north: ((id: "clk", name: "CLK", clock: true),),
+    ),
+  )
+
+  // -----------------------------------------------------------------
+  // 4) Two pentagon-ported blocks connected by a wire
+  //    (wire terminates at outer edge of each pentagon)
+  // -----------------------------------------------------------------
+  element.block(
+    id: "src", w: 2, h: 1.5, x: 0, y: -5,
+    name: "src", name-anchor: "center",
+    fill: util.colors.pink,
+    port-shape: "pentagon",
+    ports: (east: ((id: "q", name: "Q", kind: "out"),)),
+  )
+  element.block(
+    id: "dst", w: 2, h: 1.5, x: 6, y: -5,
+    name: "dst", name-anchor: "center",
+    fill: util.colors.blue,
+    port-shape: "pentagon",
+    ports: (west: ((id: "d", name: "D"),)),
+  )
+  wire.wire("w-sd", ("src-port-q", "dst-port-d"))
+
+  // -----------------------------------------------------------------
+  // 5) Group with pentagon ports enclosing a child block
+  // -----------------------------------------------------------------
+  element.group(
+    id: "g", name: "group w/ pentagon ports", name-anchor: "north",
+    stroke: (dash: "dashed"),
+    fill: util.colors.purple.lighten(70%),
+    padding: 2em,
+    port-shape: "pentagon",
+    ports: (
+      west: ((id: "in",  name: "IN"),),
+      east: ((id: "out", name: "OUT", kind: "out"),),
+    ),
+    {
+      element.block(
+        id: "inner", w: 2, h: 1.5, x: 12, y: -5,
+        fill: util.colors.green,
+        ports: (west: ((id: "d"),), east: ((id: "q"),)),
+      )
+    },
+  )
+  wire.wire("wgi", ("g-port-in",  "inner-port-d"))
+  wire.wire("wgo", ("inner-port-q", "g-port-out"))
+})

src/elements/block.typ

@@ -16,6 +16,10 @@
 /// Draws a block element
 ///
 /// #examples.block
+///
+/// Ports can be given a pentagon shape (with configurable direction, size,
+/// stroke and fill) via `port-shape` and per-port overrides:
+/// #examples.port-shape
 /// For other parameters description, see #doc-ref("element.elmt")
 /// - radius (number, length, ratio, dictionary): The corner radius of the block. See CeTZ documentation for more information
 #let block(
@@ -27,6 +31,10 @@
   name-anchor: "center",
   ports: (),
   ports-margins: (),
+  port-name-padding: 2pt,
+  port-shape: none,
+  port-kind: "in",
+  port-size: 1em,
   fill: none,
   radius: 0.5em,
   stroke: black + 1pt,
@@ -44,6 +52,10 @@
   name-anchor: name-anchor,
   ports: ports,
   ports-margins: ports-margins,
+  port-name-padding: port-name-padding,
+  port-shape: port-shape,
+  port-kind: port-kind,
+  port-size: port-size,
   fill: fill,
   stroke: stroke,
   id: id,

src/elements/element.typ

@@ -37,6 +37,10 @@
 ///   - `clock` (`bool`): Whether it is a clock port (triangle symbol)
 ///   - `vertical` (`bool`): Whether the name should be drawn vertically
 /// - ports-margins (dictionary): Dictionary of ports margins (used with automatic port placement). They keys are cardinal directions ("north", "east", "south", "west"). The values are tuples of (`<start>`, `<end>`) margins (numbers)
+/// - port-name-padding (number, length): Padding between the port name label and the port anchor point (default `2pt`)
+/// - port-shape (none, str): Default port shape for all ports of this element. Set to `"pentagon"` to draw pentagon-shaped ports. Overridable per port via the port's `shape` field. See #examples.port-shape
+/// - port-kind (str): Default direction of ports (`"in"` or `"out"`). Overridable per port via the port's `kind` field
+/// - port-size (length): Default unit size of pentagon-shaped ports (default `1em`). Overridable per port via the port's `size` field
 /// - fill (none, color): Fill color
 /// - stroke (stroke): Border stroke
 /// - id (str): The block id (for future reference)
@@ -56,6 +60,10 @@
   name-anchor: "center",
   ports: (:),
   ports-margins: (:),
+  port-name-padding: 2pt,
+  port-shape: none,
+  port-kind: "in",
+  port-size: 1em,
   fill: none,
   stroke: black + 1pt,
   id: "",
@@ -140,7 +148,13 @@
       tl, tr, br, bl,
       ports,
       ports-margins,
-      debug: debug.ports
+      debug: debug.ports,
+      name-padding: port-name-padding,
+      port-shape: port-shape,
+      port-kind: port-kind,
+      port-size: port-size,
+      elmt-stroke: stroke,
+      elmt-fill: fill,
     )
   }
 })

src/elements/group.typ

@@ -1,9 +1,15 @@
 #import "/src/cetz.typ": draw, coordinate
 #import "../util.typ"
+#import "ports.typ": add-ports
 
 /// Draws a group of elements
 ///
 /// #examples.group
+///
+/// Ports can also be defined on a group, just like on a block. By default
+/// port labels are drawn *outside* the group border so they do not overlap
+/// child elements. Set `outside-port-names: false` to draw them inside.
+/// #examples.group-ports
 /// - body (elements, function): Elements to group
 /// - id (str): see #doc-ref("element.elmt")
 /// - name (str): The group's name
@@ -16,6 +22,14 @@
 ///    - array: either (`<all>`,), (`<vertical>`, `<horizontal>`) or (`<top>`, `<right>`, `<bottom>`, `<left>`)
 ///    - dictionary: valid keys are "top", "right", "bottom" and "left"
 /// - radius (number): The corner radius
+/// - ports (dictionary): see #doc-ref("element.elmt")
+/// - ports-margins (dictionary): see #doc-ref("element.elmt")
+/// - outside-port-names (bool): If `true` (default), port name labels are drawn outside the group border so they do not overlap child elements. Set to `false` to draw labels inside, matching the block behaviour
+/// - port-name-padding (number, length): Padding between the port name label and the group border (default `2pt`). Accepts anything CeTZ accepts as `padding` (number or length)
+/// - port-shape (none, str): see #doc-ref("element.elmt")
+/// - port-kind (str): see #doc-ref("element.elmt")
+/// - port-size (length): see #doc-ref("element.elmt")
+/// - debug (dictionary): see #doc-ref("element.elmt")
 #let group(
   body,
   id: "",
@@ -24,7 +38,17 @@
   fill: none,
   stroke: black + 1pt,
   padding: 0.5em,
-  radius: 0.5em
+  radius: 0.5em,
+  ports: (:),
+  ports-margins: (:),
+  outside-port-names: true,
+  port-name-padding: 2pt,
+  port-shape: none,
+  port-kind: "in",
+  port-size: 1em,
+  debug: (
+    ports: false
+  )
 ) = {
   let min-x = none
   let max-x = none
@@ -68,6 +92,25 @@
     stroke: stroke,
     fill: fill
   )
+
+  add-ports(
+    id,
+    id + ".north-west",
+    id + ".north-east",
+    id + ".south-east",
+    id + ".south-west",
+    ports,
+    ports-margins,
+    debug: debug.ports,
+    outside-name: outside-port-names,
+    name-padding: port-name-padding,
+    port-shape: port-shape,
+    port-kind: port-kind,
+    port-size: port-size,
+    elmt-stroke: stroke,
+    elmt-fill: fill,
+  )
+
   if name != none {
     draw.content(
       id + "." + name-anchor,

src/elements/ports.typ

@@ -1,36 +1,89 @@
 #import "/src/cetz.typ": draw
-#import "../util.typ": rotate-anchor
+#import "../util.typ": rotate-anchor, opposite-anchor, port-shape-vertices
 
 #let add-port(
   elmt-id, side, port, pos,
   prev: none,
   next: none,
-  debug: false
+  debug: false,
+  outside-name: false,
+  name-padding: 2pt,
+  port-shape: none,
+  port-kind: "in",
+  port-size: 1em,
+  elmt-stroke: black + 1pt,
+  elmt-fill: none,
 ) = {
   let name = port.at("name", default: "")
   let name-rotate = port.at("vertical", default: false)
+  let is-clock = port.at("clock", default: false)
 
-  if (port.at("clock", default: false)) {
+  // Per-port overrides fall back to element-level defaults.
+  let shape = port.at("shape", default: port-shape)
+  let kind  = port.at("kind",  default: port-kind)
+  let size  = port.at("size",  default: port-size)
+  let shape-stroke = port.at("stroke", default: elmt-stroke)
+  // Pentagon fill defaults to the element's fill (so the pentagon covers the
+  // block-border segment it crosses). Clock ports default to gray. Per-port
+  // `fill` overrides both.
+  let shape-fill = port.at("fill",
+    default: if is-clock and shape == "pentagon" { gray } else { elmt-fill })
+
+  // When shape is enabled, wire-connection anchor moves outside the block, and
+  // inside-name labels reference the inner tip/base; otherwise both collapse to
+  // the boundary point (unchanged behaviour).
+  let outer-pos = pos
+  let inner-pos = pos
+
+  if shape == "pentagon" {
+    let sh = port-shape-vertices(side, kind, size)
+    let v = sh.vertices.map(off => (rel: off, to: pos))
+    draw.line(
+      v.at(0), v.at(1), v.at(2), v.at(3), v.at(4),
+      close: true,
+      stroke: shape-stroke,
+      fill: shape-fill,
+    )
+    outer-pos = (rel: sh.outer, to: pos)
+    inner-pos = (rel: sh.inner, to: pos)
+  } else if is-clock {
     if prev == none or next == none {
       panic("Clock port must have previous and next positions")
     }
-    
-    let size = if port.at("small", default: false) {8pt} else {1em}
+
+    let csize = if port.at("small", default: false) {8pt} else {1em}
     let offset
-    if      (side == "north") { offset = (    0, -size) }
-    else if (side == "east")  { offset = (-size,     0) }
-    else if (side == "south") { offset = (    0,  size) }
-    else if (side == "west")  { offset = ( size,     0) }
+    if      (side == "north") { offset = (    0, -csize) }
+    else if (side == "east")  { offset = (-csize,     0) }
+    else if (side == "south") { offset = (    0,  csize) }
+    else if (side == "west")  { offset = ( csize,     0) }
 
     let pos1 = (rel: offset, to: pos)
 
     // TODO: use context or vectors to have the height relative to the width
     draw.line(prev, pos1, next)
   }
+
+  // When outside-name is true (e.g. for groups) the label is placed on the
+  // exterior of the element border so it does not overlap child elements.
+  // Horizontal labels: anchor = opposite of the side (e.g. east port → west-anchored text, outside).
+  // Vertical labels:   same opposite side but rotated 90°, keeping text readable.
+  let name-anchor = if outside-name {
+    if name-rotate { rotate-anchor(opposite-anchor(side)) }
+    else           { opposite-anchor(side) }
+  } else {
+    if name-rotate { rotate-anchor(side) } else { side }
+  }
+
+  // Label sits at the outer edge of the shape for outside-name, inner edge for
+  // inside-name. `name-padding` is thus naturally measured from the shape edge
+  // (or from the boundary when shape is disabled).
+  let label-pos = if outside-name { outer-pos } else { inner-pos }
+
   draw.content(
-    pos,
-    anchor: if name-rotate {rotate-anchor(side)} else {side},
-    padding: 2pt,
+    label-pos,
+    anchor: name-anchor,
+    padding: name-padding,
     angle: if name-rotate {90deg} else {0deg},
     name
   )
@@ -38,7 +91,7 @@
 
   if debug {
     draw.circle(
-      pos,
+      outer-pos,
       name: id,
       radius: .1,
       stroke: none,
@@ -47,7 +100,7 @@
     
   } else {
     draw.hide(draw.circle(
-      pos,
+      outer-pos,
       radius: 0,
       stroke: none,
       name: id
@@ -60,7 +113,14 @@
   tl, tr, br, bl,
   ports,
   ports-margins,
-  debug: false
+  debug: false,
+  outside-name: false,
+  name-padding: 2pt,
+  port-shape: none,
+  port-kind: "in",
+  port-size: 1em,
+  elmt-stroke: black + 1pt,
+  elmt-fill: none,
 ) = {
   let sides = (
     "north": (tl, tr),
@@ -109,8 +169,15 @@
         pos,
         prev: pos-prev,
         next: pos-next,
-        debug: debug
+        debug: debug,
+        outside-name: outside-name,
+        name-padding: name-padding,
+        port-shape: port-shape,
+        port-kind: port-kind,
+        port-size: port-size,
+        elmt-stroke: elmt-stroke,
+        elmt-fill: elmt-fill,
       )
     }
   }
-}
+}

src/util.typ

@@ -90,6 +90,55 @@
   ).at(anchor)
 }
 
+/// Returns the pentagon port shape vertices and the outer/inner anchor
+/// offsets for the given side and direction.
+///
+/// The pentagon straddles the block boundary: 1 unit outside, 1 unit inside;
+/// height ±0.5 units. For `kind: "in"` the tip points into the block; for
+/// `kind: "out"` it points away.
+///
+/// - side (str): One of `"north"`, `"east"`, `"south"`, `"west"`
+/// - kind (str): `"in"` or `"out"`
+/// - u (length,number): The pentagon unit size
+/// -> dictionary: `(vertices: (..5 pairs..), outer: (dx, dy), inner: (dx, dy))`
+#let port-shape-vertices(side, kind, u) = {
+  // Base case: west port, input (tip east / into block).
+  // Vertices as (dx, dy) offsets relative to the boundary anchor.
+  let base-vertices = (
+    (-u, -u/2),
+    (-u, +u/2),
+    (u/2, +u/2),
+    (u, 0),          // tip east (inner side)
+    (u/2, -u/2),
+  )
+  // For output, mirror horizontally so the tip points west (outside).
+  if kind == "out" {
+    base-vertices = base-vertices.map(p => (-p.at(0), p.at(1)))
+  }
+  // Outer (wire-connection) and inner (inside-label) anchors for a west port.
+  // Outer is always 1u outside the boundary along the port normal; inner is 1u
+  // inside. Independent of `kind` (only the pentagon fill/tip direction change).
+  let base-outer = (-u, 0)
+  let base-inner = (u, 0)
+
+  // Rotation from west's frame to target side:
+  //   west:  identity (x, y)
+  //   north: (x, y) → (y, -x)
+  //   east:  (x, y) → (-x, -y)
+  //   south: (x, y) → (-y, x)
+  let rot = if side == "west"       { p => p }
+            else if side == "north" { p => (p.at(1), -p.at(0)) }
+            else if side == "east"  { p => (-p.at(0), -p.at(1)) }
+            else if side == "south" { p => (-p.at(1), p.at(0)) }
+            else { panic("Unknown side: " + side) }
+
+  return (
+    vertices: base-vertices.map(rot),
+    outer: rot(base-outer),
+    inner: rot(base-inner),
+  )
+}
+
 #let valid-anchors = (
   "center", "north", "east", "west", "south",
   "north-east", "north-west", "south-east", "south-west"